Biocides Against Biological Degradation of Plastics

Abstract

Biodegradation of polymers refers to the degradation and assimilation of organic polymers by living organisms, principally microorganisms such as fungi, bacteria, and actinomycetes [1]. This microbiological corrosion of plastics is very frequent and very difficult to prevent [2–4]. Some plastic materials are degraded by organisms not only under a tropical climate but also under oceanic and continental climates. Such is the case for plasticized PVC, PVAL plasticized by glycerol and its derivatives, filled phenolic resins, and polycaprolactone and its derivatives [1]. Biopolymers (cellulose, starch, polypeptides, cellophane, etc. [5]) are easily microbiologically degraded. Synthetic polymers are generally more resistant to this type of degradation, and their resistance increases with molecular weight. PE provides a typical example, as shown in Table 13.1 [1]. Polymers become more sensitive to microbiological degradation when they have already begun to degrade by UV radiation effects that produce chain scission. When a polymer becomes powdered, its surface increases manyfold and microbiological degradation may follow [7].